The goal of this study is to fabricate an intravascular glucose sensor that functions accurately for 7 days in vivo. We will utilize a glucose membrane design devised in Phase I to develop a custom outer membrane that has covalently attached bioactive sites to resist biofouling, allows for suitable glucose diffusion, and prevents leaching of potentially toxic by-products. This membrane will be applied to needle-type, amperometric glucose sensor. The versatility of the sensor design will allow easy incorporation into a patient's bloodstream through a central access catheter. The catheter will be designed for 7 day use in the intensive care unit, and will be complete with a hemostatic connector for attaching to an access line, and the electrical connections to an amplifier/display unit. The final prototype will be evaluated for cytotoxicity, hemocompatibilty, and accuracy both using in vitro and in vivo methods. Continuous monitoring of blood glucose levels has been an elusive goal, but would greatly improve the care for critically ill patients in managing insulin therapy. PUBLIC HEALTH RELEVANCE: The goal in this grant is to make an intravascular glucose sensor that measures blood glucose levels continuously for 7 days. By maintaining sensor function, this technology will provide health care professionals with immediate changes in patient health and decrease complications. Currently sudden changes in glucose levels are not detected leading to increased health care costs and increased risks to patients.